PROJECT SUMMARY Addressing sexual trauma in the context of HIV care is essential to improve clinical outcomes and mental health among women in South Africa. Women represent nearly two-thirds of the South African HIV epidemic, and they report disproportionately high rates of sexual trauma, which negatively impacts their mental health and may lead to avoidant coping behaviors. The psychological sequaelae of trauma can adversely impact retention in HIV care and adherence to antiretroviral therapy (ART), which may in turn reduce viral suppression and increase the risk of HIV transmission to others. HIV care engagement may be particularly challenging in South Africa, where women face dual epidemics of HIV and sexual violence, with limited access to mental health treatment. In this setting, interventions that address barriers to effective HIV care engagement and improve health outcomes across the care continuum are urgently needed. The primary objective of this study is to evaluate the effectiveness of ImpACT+ (Improving AIDS Care after Trauma+), an individual-level intervention based on theories of stress and coping, on clinical outcomes among HIV-infected women with sexual trauma. Secondary objectives include determining whether reductions in traumatic stress and avoidant coping mediate intervention effects on clinical outcomes, and assessing potential for scalability and full-scale implementation. ImpACT+ was developed and culturally adapted to the South African context, targeting women who are newly initiating ART to make use of a window of opportunity in HIV care and maximize impact on care engagement. The proposed five-year study seeks to rigorously evaluate ImpACT+, using a hybrid effectiveness-implementation design (Hybrid Type I), with three specific aims: (1) evaluate the effectiveness of ImpACT+ on viral suppression, ART adherence, and HIV care engagement; (2) assess the degree to which reductions in PTSD symptoms and avoidant coping mediate intervention effects; and (3) explore potential for scalability and full-scale implementation. The trial will enroll 350 women who have newly initiated ART and have a history of sexual trauma and elevated traumatic stress. Participants will be randomized to the ImpACT+ intervention condition (six weekly sessions, with six maintenance check-ins over the 12-month follow-up period) or the control condition (three weekly sessions of Problem Solving Therapy (PST)). All participants will complete a baseline assessment at enrollment (within four months of initiating ART), with additional behavioral assessments and viral load testing at 4-month, 8-month, and 12-month follow-up. ART adherence will also be assessed using dried blood spot (DBS) biomarkers, and care engagement data will be extracted from medical records at the end of the study period. This study is one of the first full-scale trials of a trauma-informed intervention on clinical outcomes for HIV-infected women. If effective, ImpACT+ will fill a critical void in evidence-based trauma interventions in this setting and combat the drop-off across the HIV continuum of care in South Africa, as well as inform such approaches in the U.S. and globally.